This invention relates to the field of testing for explosives and more particularly, using a testing unit capable of detecting trace amounts of explosives such as an ion trap mobility spectrometer to analyze the constituents of air extracted from the interior of a piece of baggage to determine whether the baggage contains explosives.
Aircraft, particularly those operated by passenger airlines, are considered terrorist targets. Thus, aviation security is essential to the safety of airline passengers. One attempt to minimize the possibility of a terrorist attack includes screening all baggage (i.e., luggage) that enters the aircraft. Specifically, both carry-on and checked baggage are screened for bombs and/or explosives.
Some of the current methods used to screen carry-on and checked baggage include manual inspection, X-ray, and trace detection. Manual inspection is invasive and often time consuming. Utilizing X-ray equipment is a non-invasive procedure. However, that method requires the operator of the X-ray equipment to promptly recognize the particular shape of the explosive device.
Trace detection is also less intrusive than manual inspection. One current trace detection technique includes swabbing the exterior of a piece of baggage and placing the swab in front of a testing unit capable of detecting trace amounts of explosives. One such testing unit is an ion trap mobility spectrometer, such as the VaporTracer2(copyright) sold by Ion Track Instruments in Lowell, Mass. FIG. 1 illustrates a VaporTracer2(copyright) ion trap mobility spectrometer 100. That ion trap mobility spectrometer 100 includes a start button 102, a control keypad 104, a LCD display 106 and a nozzle 108.
The nozzle 108 illustrated in FIG. 1 includes a preconcentrator 110. A more detailed illustration of one embodiment of a preconcentrator 110 is shown in FIGS. 2A and 2B. The preconcentrator 110 includes an orifice 202, a pair of electrodes 204 and a heating coil (not shown). The end of the preconcentrator 110 that includes the electrodes 204 is generally inserted into the ion trap mobility spectrometer 100. The orifice 202 allows air to pass from one end of the preconcentrator 110 to the other end.
For example, after the swab is passed over the exterior surface of the baggage, the swab is either placed in front of or rubbed onto the preconcentrator 110. The ion trap mobility spectrometer 100 includes a small vacuum unit (not shown) which draws the air and any constituents through the preconcentrator 110. For the purpose of this invention, the term xe2x80x9cconstituentsxe2x80x9d shall mean both particles in the air and vapor molecules. As the constituents pass through the preconcentrator 110, the heating coil volatizes the constituents, thereby creating vapors that can be detected by the ion trap mobility spectrometer 100. Accordingly, if the exterior of the bag includes trace amounts of explosives, the ion trap mobility spectrometer 100 will recognize the constituents as such.
Another possible trace detection technique includes placing the nozzle 102 of the ion trap mobility spectrometer 100 directly into the baggage and analyzing a sample of air within the baggage to determine whether the air contains explosive particles or vapors. However, placing the nozzle 102 directly into a piece of baggage and drawing an air sample therefrom is impractical and inefficient. Specifically, unless the entire ion trap mobility spectrometer 100 is placed within the baggage and the baggage is closed, the ion trap mobility spectrometer 100 will draw in a substantial amount of air from outside the baggage in addition to the air drawn from within the baggage, thereby obtaining a possibly erroneous sample and reading.
Furthermore, although the ion trap mobility spectrometer 100 includes a vacuum unit, the vacuum may not have enough capacity to effectively draw air from a normally sized piece of baggage. Moreover, the vacuum unit in the ion trap mobility spectrometer may not be large enough to efficiently screen multiple pieces of baggage. That is, depending upon the size of each piece of baggage, it may take several minutes for the ion trap mobility spectrometer to extract a sufficient volume of air from the baggage in order to produce an accurate reading. Assuming a single ion trap mobility spectrometer is used to screen several pieces of baggage, the overall efficiency for this technique would reduce even further. Moreover, not only must a sufficient volume of air be extracted from the baggage, but it is preferable to extract the air at a moderately high flow rate to produce an accurate reading. Thus, if the size of the baggage is relatively large, the vacuum unit included within the ion trap mobility spectrometer may be unable to extract an adequate volume of air at a rate sufficient to produce a meaningful test.
It is an object of the invention to determine whether explosives are contained within a piece of baggage.
It is another object of the invention to determine whether explosives are contained within a piece of baggage via sampling the air within the baggage.
It is another object of the invention to analyze the constituents of the air sample extracted from the interior of a piece of baggage.
It is a further object of the invention to analyze the constituents of the air sample extracted from the interior of a piece of baggage in a more efficient manner.
It is a further object of the invention to extract the air sample through the zipper of the baggage.
It is further object of the invention to collect the constituents of air in a preconcentrator from an ion mobility spectrometer.
It is even a further object of the invention to create an interface between the baggage and the preconcentrator.
The present invention is an interface between a piece of baggage and a preconcentrator. For the purposes of this invention, such an interface shall be referred to as a baggage-preconcentrator interface. The baggage-preconcentrator interface is able be secured to the opening in the baggage, such as an opening created by a zipper. After the baggage-preconcentrator interface is clamped to the teeth of the zipper and the zipper is closed, the preconcentrator is firmly and securely inserted into the baggage-preconcentrator interface because the shape of such interface matingly engages the preconcentrator. The baggage-preconcentrator interface, therefore, provides a securing mechanism through which an air sample may be extracted from the interior of the baggage and through the preconcentrator.
Accordingly, one embodiment of the baggage-preconcentrator interface includes a top securing member, a bottom securing member connected to said top securing member and forming a gap between it and the top securing member, and a recess corresponding to the exterior shape of a preconcentrator, wherein the recess comprises a vent that allows air to pass from the interior of the bag to the preconcentrator. It may also be preferable for the baggage-preconcentrator interface to include two clamps diametrically opposed from one another, wherein each of said clamps comprises bottom and top lips thereby creating a gap therebetween, and a lever connected to said top lip, thereby allowing the opening of the gap to be adjusted when the levers are squeezed and/or released.
The baggage-preconcentrator interface provides a convenient entry point from which to extract air from the interior of baggage. Moreover, the shape of such interface corresponds to that of the preconcentrator. Thus, an air sample passes through both the interface and the preconcentrator. Because the air sample passes through the preconcentrator, the constituents of air collect therein. Therefore, the baggage-preconcentrator interface of the present invention allows a truly representative sample of air and its constituents to be extracted from the interior of the bag. Assuming explosives reside in the baggage, the constituents of the air will include trace amounts of such explosives, which will collect in the preconcentrator as the air sample is extracted from the baggage. Thereafter, a testing unit capable of detecting trace amounts of explosives, such as an ion mobility spectrometer, can analyze the constituents collected in the preconcentrator and determine whether any of the constituents are explosive.
For example, the manner in which such a baggage-preconcentrator interface could be used in the process of analyzing the constituents of air within a piece of baggage is as follows: inserting a baggage-preconcentrator interface within a piece of baggage; inserting the preconcentrator into the recess of the baggage-preconcentrator interface; extracting air from the interior of the piece of baggage and through the vent in the baggage-preconcentrator interface and through the orifice in the preconcentrator, the preconcentrator collecting constituents of the air as the air passes therethrough; removing the preconcentrator from the baggage-preconcentrator interface; placing the preconcentrator into a testing unit capable of detecting a trace amount of an explosive; and analyzing the constituents by drawing the constituents from the preconcentrator into the testing unit and operating the testing unit to determine whether any of the constituents correspond to an explosive.